1. Technical Field
The present disclosure relates generally to laser-treated silicon substrates that are capable of gettering, and methods of making getters by laser treatment of a silicon substrate.
2. Description of Related Art
Getters are reactive materials used for removing traces of gas or moisture from various systems, e.g., in wafer scale (or wafer-level) packaging or in semiconductor manufacturing systems. In the electronics industry, a getter material may be included within a chamber enclosing an electronic device (e.g., a micro-electro-mechanical system, or “MEMS” device) or a semiconductor package to capture condensation or gases that may collect within the chamber during processing. In some cases, a getter is included within a vacuum packaged electronic device to minimize the effects of any out-gassing that may occur within the package. Getters are also used in field emission displays (FEDs).
MEMS devices are commonly made with single crystal Si or polysilicon, making it possible to fabricate them in semiconductor FABs. However, to achieve economy of scale in packaging MEMS devices, it is required to protect the released MEMS structure through the packaging line. Alternatively, wafer-level packaging can be employed. In either case, the MEMS is typically protected by another piece of silicon with an open cavity to allow the MEMS structure to move. Condensation within this cavity after it is sealed is another common problem, leading to device failure or device reliability issues due to changes in performance over time. Condensation of any kind is detrimental to the functioning of MEMS devices in particular, as it may cause the MEMS structure to stick to neighboring surfaces. Condensation can also change the mass of the MEMS structure, changing is responsivity.